peak

So very sorry to inform you this: update all didn't work on my MacBook Pro. Worked fine on my iMac. Both running Catalina 10.15.3. All apps installed in ~/Applications on both machines. On the MacBook Pro: open each app, all show the "Software Update" dialog window, click the "Install Update" button, the "Software Update" dialog went away and nothing happen. Reboot and try again...same Just manually download and install for now.

Document -> Transparent Background Is this it?

The Mac Preview app, you can export to PNG and de-select Alpha channel. Can Affinity Photo do this? The reason I want this is because the Apple App Store icons do not allow PNG with alpha channel.

Yes. I solved the problem. It's just one extra step in Catalina... Thanks!

So right after dismissing the "Cannot open..." system dialog box, open the "Security & Privacy" system pref, it'll show "... app was blocked from opening..." with an "Open Anyway". Kind of the same as previous version of macOS. Thanks!

okay. would love to learn where that switch is. please let me know when you are at you iMac.

In Catalina, I don't see any options in "System Preferences"/"Security & Privacy" to disable notarization requirement... The old trick of right-click open app no longer work. I believe if the app is signed by the developer, then it must be notarized by Apple. Maybe some command line tool can turn this off. I haven't found any answer so far...all I see any signed app must be notarized.

On MacOS Catalina Beta, running the app is blocked with system message: I am pretty sure you just need to notarize your apps. Very unlikely, but in case you have heard yet, for this video: https://developer.apple.com/videos/play/wwdc2019/703/ Can you get you apps ready for Catalina by notarizing them now? They will still work on Mojave...